NQA association mechanism:
Association indicates that NQA provides detection and notifies the associated module of the detection result. Then the associated module processes services based on the detection result. NQA can be associated with VRRP, static route, backup interface, IGMP proxy, IP address pool, DNS server, and PBR.
Static route is used as an example:
A static route with the next hop address of 192.168.0.88 is configured. If the next hop address of 192.168.0.88 is reachable, the static route is valid. If the next hop address of 192.168.0.88 is unreachable, the static route is invalid. After association is configured, the static route can be determined in real time. If NQA detects that the next hop address of 192.168.0.88 is unreachable, NQA notifies the static route module. The static route module determines that the static route is invalid.

Common NQA query commands on the AR router:
Run the display nqa-parameter command in the NQA view to check parameter settings of the NQA test instance.
Run the display nqa history command in any view to check historical statistics about the NQA test instance.
Run the display nqa results command in any view to check NQA test instance results.

On an AR router, use VRRP and NQA association to detect uplink faults and switch over between master/backup gateways. The configuration roadmap is as follows:
1. Configure IP addresses and routing protocols for different device interfaces to enable network-layer routers to be reachable.
2. Configure a VRRP group on Router A and Router B. Set priority to 120 and preemption delay to 20s on Router A and configure Router A as a master device. Set priority to a default value and configure Router B as a backup device to implement active/standby backup of gateways.
3. On Router A, configure an ICMP-type NQA test case and an IP address of a Router E interface as the destination, and check the link connectivity between Router A and Router E interfaces.
4. On Router A, configure VRRP and NQA association. When the NQA detects a link fault, it triggers the VRRP group to implement master/backup switchover.
For details about the configuration, see the URL: Example for Configuring Association Between VRRP and NQA to Monitor the Uplink Status.